Table 2. [Clinical Findings in POLG-Related Disorders]. - GeneReviews®

System	Manifestation	% of Persons w/Manifestation
Neurologic	Epilepsy (incl myoclonic, focal motor & generalized seizures, status epilepticus, & epilepsia partialis continua)	~70%
Tone abnormalities (most commonly hypotonia)	~50%
"Cerebrovascular" involvement (incl migraines & stroke-like episodes)	~36%
Movement disorder (incl extrapyramidal movement disorders such as parkinsonism & chorea, & cerebellar ataxia)	~60%
Peripheral neuropathy (sensory neuronopathy / ganglionopathy & axonal sensorimotor neuropathy ¹)	~53%
Headache (migraine-like)	~36%
Gastrointestinal	Liver issues (most notably liver failure that is either spontaneous or precipitated by valproic acid or sodium divalproate in children)	~64%
Gastrointestinal dysmotility (incl vomiting, diarrhea, & feeding difficulties)	~6%-52%
Ophthalmologic	Cataracts	~7%
Ptosis & external ophthalmoplegia	~34%-38%
Cortical blindness	~30%
Retinopathy	~2%
Audiologic	Sensorineural hearing loss	~11%
Neuromuscular/ myopathy	Proximal or distal myopathy	~70%
Exercise intolerance	Common in adolescence & adult-onset phenotypes
Endocrine	Primary ovarian failure & ovarian dysgenesis	Rare
Primary testicular failure	Rare
Diabetes mellitus	~1%
Renal	Renal tubular acidosis, renal failure, renal stones	~11% (MCHS)
Respiratory	Ventilatory Weakness (muscle, nerve, central respiratory drive)	~12%

System

Manifestation

% of Persons w/Manifestation

Neurologic

Epilepsy (incl myoclonic, focal motor & generalized seizures, status epilepticus, & epilepsia partialis continua)

~70%

Tone abnormalities (most commonly hypotonia)

~50%

"Cerebrovascular" involvement (incl migraines & stroke-like episodes)

~36%

Movement disorder (incl extrapyramidal movement disorders such as parkinsonism & chorea, & cerebellar ataxia)

~60%

Peripheral neuropathy (sensory neuronopathy / ganglionopathy & axonal sensorimotor neuropathy ¹)

~53%

Headache (migraine-like)

~36%

Gastrointestinal

Liver issues (most notably liver failure that is either spontaneous or precipitated by valproic acid or sodium divalproate in children)

~64%

Gastrointestinal dysmotility (incl vomiting, diarrhea, & feeding difficulties)

~6%-52%

Ophthalmologic

Cataracts

~7%

Ptosis & external ophthalmoplegia

~34%-38%

Cortical blindness

~30%

Retinopathy

~2%

Audiologic

Sensorineural hearing loss

~11%

Neuromuscular/
myopathy

Proximal or distal myopathy

~70%

Exercise intolerance

Common in adolescence & adult-onset phenotypes

Endocrine

Primary ovarian failure & ovarian dysgenesis

Rare

Primary testicular failure

Rare

Diabetes mellitus

~1%

Renal

Renal tubular acidosis, renal failure, renal stones

~11% (MCHS)

Respiratory

Ventilatory Weakness (muscle, nerve, central respiratory drive)

~12%

From: POLG-Related Disorders

GeneReviews^® [Internet].

Adam MP, Feldman J, Mirzaa GM, et al., editors.

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